Kidney Disease Linked to Cognitive Impairment: From the Annual Meeting of the American Academy of Neurology

Kidney Disease Linked to Cognitive Impairment: From the Annual Meeting of the American Academy of Neurology

Article excerpt

HONOLULU - Patients with moderate chronic kidney disease had a higher prevalence of moderate cognitive impairment than did patients receiving hemodialysis in a prospective pilot study conducted at two clinics.

"Clinicians think about the apo E4 gene, advanced age, education level, and history of stroke as being risk factors for cognitive impairment, but they don't think about chronic kidney disease as a risk factor," Dr. Anne M. Murray said in an interview during a poster session at the meeting. "It's a strong risk factor."

Recent studies suggest a link between estimated glomerular filtration rate (GFR) and cognitive function, but the severity of cognitive impairment and effects on specific cognitive domains remain unknown said Dr. Murray, a geriatrician and neuro-epidemiologist at Hennepin County Medical Center, Minneapolis.

She and her associates at two Minneapolis clinics compared the frequency of mild, moderate, and severe cognitive impairment in 81 patients with an estimated GFR of less than 50 mL/min per 1.73 [m.sup.2] (stage 3B to stage 5 chronic kidney disease) against 338 hemodialysis patients and 101 controls. The patients with chronic kidney disease had a mean estimated GFR of 31 mL/min per 1.73 [m.sup.2]. The researchers administered a 45-minute battery of nine validated neuropsychological tests to patients with chronic kidney disease (CKD) and to controls, while hemodialysis patients were tested before dialysis, 1 hour after, or on the day after dialysis. They used the Modified Mini-Mental State Examination (maximum score, 100) to measure global cognitive function, and other tests to measure performance in the domains of memory, executive function, and language.

African Americans made up 59% of the CKD group, 11% of the hemodialysis group, and 8% of controls. Mean ages in the CKD, hemodialysis, and control groups were 60, 71, and 69 years, respectively. …